Pre-Exposure Prophylaxis Studies (PrEP)

The following studies are investigating the effectiveness of pre-exposure prophylaxis (PrEP) strategies, which include administering antiretroviral drugs – medications that are used to treat HIV infections because they interfere with the life-cycle of retroviruses such as HIV – to healthy people to reduce the risk of infection.

iPrEx evaluated the effectiveness of a PrEP strategy involving the daily use of Truvada®, which has been shown to have a protective effect on preventing HIV infection in HIV-negative individuals. Truvada is the combination of two antiretroviral medications, emtricitabine and tenofovir disoproxil fumarate, which treats HIV infections by preventing the virus from multiplying in the body. These drug belong to a class of antiretroviral medications called nucleoside reverse transcriptase inhibitor (NRTI). iPrEx showed that Truvada is 42% effective in reducing HIV infections overall; adherence to the daily medication regimen was strongly correlated with efficacy.

MTN-017 is the first Phase II trial of a rectal microbicide, designed to evaluate the safety, drug absorption and acceptability of reduced glycerin tenofovir gel, as well as oral Truvada, among men who have sex with men and
transgender women.

iPrEx Open-label Extension (OLE) is the first worldwide PrEP demonstration project in men who have sex with men (MSM)and transgender women. iPrEx OLE will provide additional safety data, evaluates adherence to the daily medication regimen, and assesses whether participants are more or less likely to take Truvada now that iPrEx has shown that the drug is partially effective in preventing HIV infections.

HPTN 069, or NEXT-PrEP, evaluates different medication combinations to see if they are safe and well tolerated to be used for future PrEP efficacy studies. In addition to emtricitabine and tenofovir disoproxil fumarate, HPTN 069 is also evaluating an antiretroviral medication called Selzentry®, also known as maraviroc. Selzentry belongs to a class of antiviral medications called CCR5 co-receptor antagonists.

DOT-DBS will help develop novel methods to measure HIV medications in people’s bodies. The study will see whether dried blood spots and hair samples can be used as a tool to accurately measure how often people take their pills. This tool will be very helpful for future public health strategies using anti-HIV medications to prevent infection in HIV-negative individuals.